PROTISTS

Chapter 19 - 1

3 groups of Protists:

Animal-like ProtistsAnimal-like Protists

Plant-like ProtistsPlant-like Protists

Fungus-like ProtistsFungus-like Protists

PROTISTS

All are All are eukaryoteseukaryotes – – have a nucleus and have a nucleus and membrane-bound membrane-bound organelles.organelles.

4

Endosymbiotic Endosymbiotic TheoryTheory

-How Eukaryotes came to be--How Eukaryotes came to be-Scientists think protists were the first Scientists think protists were the first eukaryotes to evolve.eukaryotes to evolve.Endosymbiosis refers to one species living Endosymbiosis refers to one species living within another (the host)within another (the host)

Movement of smaller photosynthetic & Movement of smaller photosynthetic & heterotrophic prokaryotes into larger prokaryotic heterotrophic prokaryotes into larger prokaryotic host cellshost cells

Formed cell organellesFormed cell organelles chloroplast

mitochondria

Animal-Like Protists“Protozoans”

19 - 2

PROTOZOANS

UnicellularUnicellular – made up of – made up of one one

cell.cell.

HeterotrophsHeterotrophs – they eat – they eat other organisms or dead other organisms or dead organic matter.organic matter.

ClassifiedClassified by how they by how they movemove

4 PHYLA OF PROTOZOANS

Ciliophora (Ciliates)

Sarcodina (Amoeba)

Apicomplexa (Sporozoa)

Zoomastigina (Flagellates)

PHYLUM CILIOPHORA

Ciliates – Use Cilia for movement.

found in fresh and salt waterDraw and label p.548

Phylum Cilophora

paramecium

Phylum Cilophora

Phylum Ciliophora

TWO KINDS OF NUCLEI:Macronucleus – controls daily functions such as feeding, eliminating waste, and maintaining water balance

Micronucleus – used for reproduction

Phylum Ciliophora

Reproduce Asexually, but maintain genetic variation through Conjugation: exchange genetic info

PHYLUM SARCODINA

Pseudopods- (“fake feet”) used for feeding and locomotion.Saltwater and freshwaterAsexual reproduction

Draw the example - amoeba

pseudopods

nucleus

Food vacuole

Sarcodina 3D

Sarcodina

Foraminifera - have a protective shell or TEST, usually made of calcium carbonate

layers of tests can deposit on the ocean floor

these can form limestone and chalk, like the White Cliffs of Dover

Some species of forams are good indicators of oil deposits below

Cliffs of Dover

PHYLUM APICOMPLEXA

Sporozoans- Form spores at some point in their life cycle.Lack locomotionSexual and Asexual reproductionIntestinal parasites

Plasmodium (Malaria)

It’s Vector: Anopheles Mosquito

Phylum Apicomplexa

Malaria in red blood cells

PHYLUM ZOOMASTIGINA

Flagellates- move using flagella

Free living by absorbing dead or decaying organic matter OR some are parasites

EX:Trichonympha lives in the gut of termites (helps termite digest wood)

Trichomonas Trichomonas vaginalis: vaginalis: an STDan STD

Zoomastigina

Tsetse Fly: carries Trypanosoma to humans; in other words, it’s a Vector for African Sleeping Sickness

American Sleeping Sickness (Chagas disease) – carried by reduviid bug

Phylum Zoomastigina

Plant-Like Protists“Algae”

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PROTISTS

PLANT-LIKE PROTISTSMost perform photosynthesisContain chlorophyll (green pigment) and possibly secondary pigmentsClassified by their pigment color

ALGAE

Phyla of AlgaeDiatoms - BacillariophytaDinoflagellates - PyrrophytaEuglenoids - EuglenophytaYellow/Green algae - ChrysophytaBrown algae - PhaeophytaGreen algae - ChlorophytaRed algae - Rhodophyta

DIATOMS

Phyla of AlgaeDiatoms- “The Golden Boxes”Made of chlorophyll (green) & carotenoids (golden-yellow)Reproduction- sexual and asexual.Cell wall- made of hard silica (glass)

Diatoms

Made of 2 halves: The smaller half fits inside the bigger half, like a box and lid.Store their food as oil, so they float at the top of the water where they can get sunlight for photosynthesis.

Dinoflagellate

DINOFLAGELLATES

Phyla of AlgaeDinoflagellates- “The spinning ones”2 flagella at right angles to eachother, causes it to spin as it moves.Mostly found in saltwater.Can be bioluminescent: Glow

Dinoflagellates

ALGAL BLOOMS:In good conditions, will reproduce in GREAT numbers.Clog fish gillsDie, decompose, and deplete the oxygen supply, suffocating marine life.

Dinoflagellates

The RED TIDEDinoflagellates with red secondary pigments.Produce a lethal nerve toxinDON’T EAT THE SHELLFISH… you will die.Shellfish filter water, eating the dinoflagellates.

PROTISTS

RED TIDE

EUGLENOIDS

Phyla of AlgaeEuglenoids- “The survivors” have both plant and animal characteristics.Use photosynthesis or absorb nutrients from the environment like a heterotroph.

Euglenoids

Have an “eye spot” that is sensitive to light.

CHRYSOPHYTES

Phyla of AlgaeChrysophytes- “The Colonists”Yellow-Brown secondary pigments (carotenoids)Form colonies- a group of cells that live in close association.

Brown Algae

Phyla of AlgaeBrown algae- “The Brown Ones”Fucoxanthin pigmentsMulticellularLargest algae

Ex: Giant Kelp can grow up to 30-60 cm a day.

Brown Algae

Used to make a variety of productsAs a thickening agent in puddings, ice creamUsed as food for animals (processed)

Brown Algae

GREEN ALGAE

Phyla of AlgaeGreen algae- “The Green Ones”Mostly freshwaterVery similar to plant cell wallsChloroplasts w/ chlorophyll pigments

Green Algae

Scientists think the first plants may have evolved from green algae.

RED ALGAE

Phyla of AlgaeRed algae- “The Red Ones”Warm saltwater habitatsPerform photosynthesis

Even at depths of 100 meters!

Red & blue secondary pigments (phycobilins).

Red Algae

Seaweed

Red Algae

Example: Red moss

Fungus-Like Protists

19 - 4

FUNGUS-LIKE PROTISTS

FUNGUS-LIKE PROTISTS

(MOLDS and MILDEWS)

Most are small and live in damp/dark places.Protists that act as decomposers are called molds.Classified by body form.

Fungus-like protists

3 types:Acellular slime moldsCellular slime moldsWater molds and Downy mildews

SLIME MOLDS

Use spores to reproduce.Feed on decaying matter.Absorb nutrients through cell wall.

SLIME MOLDS

ACELLULAR SLIME MOLDSPhylum Myxomycota

“Not Cellular”Can grow as much as 50 grams and 30cm and be as large as a human hand (one cell!)Single cell with many nuclei

Myxomycota - plasmodium

Myxomycota

http://biodidac.bio.uottawa.ca/ftp/BIODIDAC/Protista/Myxomyco/diagbw/Myxo005b.gif

Myxomycota Life Cycle

SLIME MOLDS

CELLULAR SLIME MOLDSPhylum Acrasiomycota

Single cellsCan congregate to form one slug-like organism.Ex. Dictyostelium

Phylum Acrasiomycotaaggregating

amoebas

colony & fruiting body

http://sps.k12.ar.us/massengale/algal__fungal_protist_notes_b1.htm

Acrasiomycota Life Cycle

Oomycota

WATER MOLDS and DOWNY MILDEW

DecomposersSurround food source with a mass of threads, break down tissues, and absorb nutrients.Downy mildew: Irish Potato famine.

http://agronomia.uchile.cl/webcursos/microbiologiagral/pagina%20microbiologia1/micologia/fotos/oomycota.gif

Examples:

water molds

downy mildews

white rusts

Oomycota Life Cycle

http://protist.i.hosei.ac.jp/PDB/Galleries/Klos/Bavaria/Leptomitus_1.html

http://www.anselm.edu/homepage/jpitocch/genbios/28-x2-PowderyMildew.jpg

Phylum Oomycota

potatoes are native to North America they were introduced to Europe and became a staple of the dietduring the summer of 1846 most of the potato crop was destroyed by Phytophthora (an oomycota)nearly 1,000,000 Irish people died, and 1,500,000 emigrated to other countries, like the U.S.

PROTISTS

IMPORTANCE OF PROTISTSECOLOGICAL ROLES

Provide an essential food base in aquatic food chainsCarry out more than 30-40% of Earth’s photosynthesisProtozoans help keep the number of bacteria in check